2700 TWIN T DRUMMER

This modules is based on the traditional drum voices of old. The type in that old organ in the charity shop, even that cr78! They all share a similar design. This specific module is using the approach of nand gates to make a dulled sine wave circuit to make the drums, you can adjust how they decay with the front knobs.

Its based on the circuit used in the Rhythm Generator from practical electronics january 1978, link to an archiive copy click here.

It has 6 input sockets, Kick, Low, High, Clave, Snare and noise, the snare is a combination of Low and Noise as per many organ drum machines of old.

It has 6 outputs so you can isolate certain voices or use the mix output.

It has a decay control for each of the Twin T voices. (In order to calibrate it, turn the Decay to max and then adjust the preset potentiometer poking through the front until it stops feedbacking.

The module is built on this approach but has been modified to work with modular synths better and also the circuit is tweaked a bit here and there after messing about with it for a while.

This approach uses the 4011 chip, the 4011AE works much better than the 4011B in this design, the 4011AE is an older version of the 4011 with different outputs and it is what the Rhythm Generator was based on. The internal buffers in the 4011B dull the decay. So keeping true to the Rhythm Generator go for the 4011AE its much suggested. You can still pick these up easily on eBay and some online retailers still stock them, but eBay is the best bet!

If you dont want to build it a sample pack is available here on Patreon

A BUILD VIDEO IS IN THE WORKS FOR THIS MODULE. ITS QUITE A BUSY MODULE SO IT IS ONE OF THE MORE ADVANCED SOLDER JOBS OF THE KOSMO MODULES.

If you live in the US or that side of the world @RIGGIDYBOO has made a bill of material with links that will work for you, as the links I include are mainly UK, you can see that bill of materials in the build thread on the forum click here